Kawasaki/GG Suspension Swap: Anyone Care?

[coopernicus]

I've been slowly working on swapping suspension from Kawasakis I have with the GGs I have...Does anyone care to know what I find? I am fortunate to have never thrown away much of anything dirt bike related so I have some "real" Ohlins shocks from a 1997 KX on my 2000 300ec and I have a KYB Factory Connection revalved 1999 KX shock that I will try over the winter. The KX and GG shocks have the exact same mounts at the top and bottom only the lengths are different by a small amount. The KX Ohlins is shorter so I bought the different length pull rods to even out the height a little. Overall the KX Ohlins shock works much better than the GG Ohlins but it could be because it is fresh. The KYB shock is closer in length to the GG Ohlins but it is still a little shorter requiring the non-standard pull rods to pull the back end up a little. If I had to guess I would say that it will be about perfect based on how it works on the KX 250 I have. Once I have the shocks figured out I will go to the Forks. I will try the FC revalved KYBs and also a set of Ohlins to see how they compare to the stock WP 43s (okay but harsh) and the Marzocchi Shivers (LTR revalved, I think, and they work fine) on the 2007 GG. I'll post results and info as I get them!

Eric

 

[roostafish]

Keep us posted. It'll be interesting to see if the forks are an improvement.

 

[bchatt]

Interesting. I spent quite a few years on KDX's and made myself 3 or 4 different length pull rods (dog bones). Longer rods that lowered the rear stabilised the bike heaps at higher speeds on open ground, but the trade off in the woods was noticable i.e slow heavy turning. Just a couple of mm difference in hole centers makes a big difference in ride height.
I believe the gassers have a different linkage ratio to other bikes. I have been told the ratio ramps up quicker toward full stroke, than the japs tend to do. Not a very scientific observation, I know, but it's another thing to think about when comparing behaviour of different bikes etc.

 

[GMP]

Eric,

If your going to that much trouble, even if it it is for fun or curiosity, I would not use pull rods to offet different shock lengths. In addition to ride height changes the initial leverage ratio will be changed as well. Longer pull rod = more leverage. This may skew what you are trying to acheive. I would adjust the shock lengths to match the GG for a true comparison.

 

[coopernicus]

Barry, I agree with you about the pull rod changes and the stability improvement at the cost of turning precision in the woods. At first I compensated by setting the sag to about 95mm (or so) which tightened the steering somewhat but caused a bit of understeer as the pace was pushed a bit. I then pulled the forks up above the clamps as far as I could go with the stock bar mounts (about 6mm) and that tightened up the steering enough to increase the sag a little but I think another few mm raise of the forks would bring it in line with stock steering precision.

Glenn, I see your point and you are correct: The rear end works differently. The reason why I'm doing it is because, frankly, I have nothing better to do and I like to experiment! I'm on the tall and larger side (235lbs) so I run a heavy spring and I like a stiff suspension. The stock pull rods were way too short with the shorter shock and my height so I did not bother to ride it that way. The shorter pull rods raised the back to a better level so I decided to ride it. The shock action was much better controlled than the stock Ohlins, I could run the clickers in the middle of their range, acceleration bumps were absorbed like a late model YZ (they work really nicely), whoops were handled very well, and large hits were absorbed much better. I will measure the difference in length of the shocks but I believe the difference was about 5/16 of an inch (1997 KX). The 1999 KX shock is about 1/8 of an inch difference or less if I remember correctly. In sum, I guess what I'm really trying to do is see what happens if I make these changes strictly as an experiment. So far? Straight 1997 shock swap "bad"; 1997 shock swap and shorter pull rods "okay" with front end height adjustment.